Lack of Internet Connection Stops Cells from Being Created - ios

Question

I am creating an app that takes a JSON text from a server and translates it into a match schedule for a robotics tournament. I have custom cells that are filled with the data I receive from the site and they display the data for each individual match just fine. The problem is that when I put the matches into a .plist file ("data.plist") so that once the internet connection is established initially, the user doesn't necessarily need to reconnect to the internet once the app is killed in order to view the match schedule for the day. My code works perfectly until I don't connect to the internet. For some reason, the app never goes into the function that creates the cells once the internet connection fails. Please help!! Here is my code:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
aRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:#"http://jrl.teamdriven.us/source/scripts/getElimMatchResultsJSON.php"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:15.0];
aConnection = [[NSURLConnection alloc] initWithRequest:aRequest delegate:self];
if(aConnection){
receivedData = [NSMutableData data];
}
else{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"No Connection!!" message:nil delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
}
paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
jrlDirectory = [paths objectAtIndex:0];
path = [jrlDirectory stringByAppendingPathComponent:#"data.plist"];
if (![[NSFileManager defaultManager] fileExistsAtPath:#"data.plist"]) {
[[NSFileManager defaultManager] copyItemAtPath:[[NSBundle mainBundle]pathForResource:#"data" ofType:#"plist"] toPath:path error:nil];
}
dataDict = [[NSMutableDictionary alloc] initWithContentsOfFile:path];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
// Prevents data from repeating itself
[receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
[receivedData appendData: data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Connection Failed" message:nil delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
NSLog(#"Connection failed! Error - %# %#", [error localizedDescription], [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSLog(#"Success! Received %d bits of data", [receivedData length]);
// Must allocate and initialize all mutable arrays before changing them
sweet16 = [[NSMutableArray alloc]init];
quarterfinals = [[NSMutableArray alloc]init];
semi = [[NSMutableArray alloc]init];
finals = [[NSMutableArray alloc]init];
dict = [[NSMutableDictionary alloc]init];
// The error is created and can be referred to if the code screws up (example in the "if(dict)" loop)
NSError *error;
dict = [NSJSONSerialization JSONObjectWithData:receivedData options:NSJSONReadingMutableLeaves error:&error];
matchNames = [[dict objectForKey:#"ElimMatchListResults"]allKeys];
matchNames = [matchNames sortedArrayUsingSelector:#selector(compare:)];
// Categorize the matches based on the first two letters of their match names
for (NSString *name in matchNames) {
if([[name substringToIndex:2]isEqual:#"16"]){
[sweet16 insertObject:[[dict objectForKey:#"ElimMatchListResults"] objectForKey:name] atIndex:sweet16.count];
}
else if([[name substringToIndex:2]isEqual:#"Q."]){
[quarterfinals insertObject:[[dict objectForKey:#"ElimMatchListResults"]objectForKey:name] atIndex:quarterfinals.count];
}
else if([[name substringToIndex:2]isEqual:#"S."]){
[semi insertObject:[[dict objectForKey:#"ElimMatchListResults"]objectForKey:name] atIndex:semi.count];
}
else if([[name substringToIndex:2]isEqual:#"F."]){
[finals insertObject:[[dict objectForKey:#"ElimMatchListResults"]objectForKey:name] atIndex:finals.count];
}
}
headers = [NSArray arrayWithObjects:#"Sweet 16", #"Quarterfinals", #"Semifinals", #"Finals", nil];
sections = [NSArray arrayWithObjects:sweet16, quarterfinals, semi, finals, nil];
// If the dictionary "dict" gets filled with data...
if (dict) {
[[self tableView]setDelegate:self];
[[self tableView]setDataSource:self];
// Now uses data storage so that the user only needs to initially connect to the internet and then they can keep the schedule afterwords
[dataDict setObject: [NSDictionary dictionaryWithObjectsAndKeys:
[NSArray arrayWithArray:sections], #"sections",
[NSArray arrayWithArray:headers], #"headers",
nil]
forKey:#"Matches"];
[dataDict writeToFile:path atomically:YES];
}
else{
NSLog(#"%#", error);
}
}
// Set the number of sections based on how many arrays the sections array has within it
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
return [[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] count];
}
// Set the number of rows in each individual section based on the amount of objects in each array
// within the sections array
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return [[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:section] count];
}
// Set headers of sections from the "headers" array
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section{
return [[[dataDict objectForKey:#"Matches"] objectForKey:#"headers"] objectAtIndex:section];
}
// Create cells as the user scrolls
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSLog(#"Entered Final Loop");
static NSString *cellIdentifier = #"Cell";
CustomCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if(!cell){
cell = [[CustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.matchNum.text = [[[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:#"MatchID"];
cell.red1.text = [NSString stringWithFormat:#"%#",[[[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:#"Red 1"]];
cell.red2.text = [NSString stringWithFormat:#"%#",[[[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:#"Red 2"]];
cell.redScore.text = [NSString stringWithFormat:#"%#", [[[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:#"Red Score"]];
cell.blue1.text = [NSString stringWithFormat:#"%#",[[[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:#"Blue 1"]];
cell.blue2.text = [NSString stringWithFormat:#"%#",[[[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:#"Blue 2"]];
cell.bluescore.text = [NSString stringWithFormat:#"%#", [[[[[dataDict objectForKey:#"Matches"] objectForKey:#"sections"] objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] objectForKey:#"Blue Score"]];
return cell;
}
I apologize for the lengthy code, I'm just trying to make sure I got all the details in. Please ask any questions you need to in order to clarify, I'm just really stuck and flustered right now as to why it never enters the function that creates cells if it doesn't have an internet connection.

Answer 1

A couple of reactions:
Your fileExistsAtPath doesn't look right. Surely you should have fully qualified path, e.g.:
if (![[NSFileManager defaultManager] fileExistsAtPath:path]) {
[[NSFileManager defaultManager] copyItemAtPath:[[NSBundle mainBundle]pathForResource:#"data" ofType:#"plist"] toPath:path error:nil];
}
I'd also probably suggest you check the success of copyItemAtPath (either the return value or use the error parameter).
I assume you know that the data.plist will never be successfully refreshed before viewDidLoad finishes (because the connection is initiated asynchronously and you return immediately from initWithRequest). This code is just loading the last data.plist values while retrieving the new data proceeds (the previous error notwithstanding). Is that your expectation?
On top of my prior point, your connectionDidFinishLoading does not appear to be issuing a reloadData call for the table, so it seems like you'll always see the previous data. When the connection is done, connectionDidFinishLoading should call reloadData for the UITableView.
Minor, unrelated detail, but I'd probably initialize receivedData in the NSURLConnectionDataDelegate method didReceiveResponse (and only if that response was successful, too). It doesn't really belong in viewDidLoad.
I might also encourage you to check for failure of JSONObjectWithData. Some networking failures manifest themselves as a successful NSURLConnection request that returns an HTML page (!) reporting an error. That HTML page will fail JSONObjectWithData processing. You might want to abort your parsing routine if JSONObjectWithData returns nil or if the error object is not nil.

Answer 2

Found my solution. The
[[self tableView]setDelegate:self];
[[self tableView]setDataSource:self];
Was only located in the "connectionDidFinishLoading:" function, so the data sources were never set if there was no internet connection.
I really appreciated everyone's help in this problem and I have edited a lot of my code to make it work better based off of those suggestions. Thanks!